In order to determine if a camshaft meets the manufacturer's specifications, a procedure known as camshaft "degreeing" is employed. The procedure determines if, in fact, the valves are opened and closed in the precise, specified manner. This is particularly important where competition engines are concerned, since cylinder pressures/volumes are critical to engine performance. Inaccurate camshafts can rob much needed horsepower from these engines, placing the driver at a real competitive disadvantage.
The problem arises because camshafts may not always meet manufacture specifications. In addition, cam timing can be negatively impacted by tolerance stacking, and/or manufacturer's decisions to target overall performance as a goal rather than racing performance.
As already indicated, cam degreeing procedures are known, and, in fact, there are different ways to degree a camshaft, all of which provide essentially the same information. See, for example, "Essential Operations--Cam Degreeing" by Doc Fromhader in the April 1997 edition of Popular Hot Rodding. See also "How To Hot Rod Small-Block Chevy's" published by HP Books; Copyright 1976; Library of Congress #73-173702. The specific procedures are somewhat complex and need not be described here, except to note that they involve determining crank position, in degrees of rotation from top dead center (TDC), and relative to specific points on the cam shaft, e.g., the point where the cam starts to push the lifter up; where the lifter is at the lowest point of its travel; and the intake centerline. The procedure must be repeated for each lifter (intake and exhaust) for each piston. Currently, the most widely employed technique is to use a single magnetic indicator base holding a single dial indicator to record the various measurements. The base is first located on the engine block such that the dial indicator can be maneuvered into position where the indicator stem will measure the movement of a piston in the cylinder on either side of top dead center. Once top dead center (TDC) has been located, the cam degreeing procedure is commenced, moving the indicator base as necessary to record measurements for each lifter associated with each piston. It will be appreciated that the procedure is both tedious and time consuming. Moreover, the indicator base may move during measurement, or between measurements at a given location, thereby placing the accuracy of the readings into question. Thus, there remains a need for a simple, easy to use, and accurate cam degreeing device or tool which minimizes the number of adjustments and/or tool relocations.